Foldable assistive stand-up chair

ABSTRACT

A foldable assistive stand-up chair includes a base support, a chair mechanism and a driving component, and the base support includes a back frame, a chair frame, a leg frame and two armrests, wherein the chair mechanism is pivotally mounted onto the base support through the chair frame, and the driving component installed between the base support and the chair mechanism is provided for driving the chair mechanism to move the four link rods with respect to the base support for assisting a user to stand up through the support of the chair frame and the back frame.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a foldable assistive stand-up chair, and more particularly to a chair that assists a user to stand up when the user rises from the chair.

2. Description of the Related Art

With reference to FIG. 24 for a collapsible chair as disclosed in U.S. Pat. No. 7,628,450, the chair is provided for users to sit, or to lie on one's back by adjusting a control unit 71 (which is a seat rest slide 60 indicated in the specification of U.S. Pat. No. 7,628,450), so that the users can position the back of the chair horizontally backward and rest at a supine position on the chair.

Although this patent provides the desired function, users such as the elderly or mobility impaired people cannot rise from the chair due to deteriorated knee caps or weak muscles, and the aforementioned patent does not provide an effective solution.

With reference to FIG. 25 for a seating furniture as disclosed in U.S. Pat. No. 7,090,296, a design provided for lying on one's back in accordance with this patent is similar to that of U.S. Pat. No. 7,628,450, but this patent still does not come with a design of assisting users to stand up. In other words, this patent includes an element 72 similar to a hydraulic cylinder or a pneumatic cylinder, but the element 72 can be used only for driving a backrest to be elevated and providing a shock absorbing effect during the elevation process. In FIGS. 2 and 3 of U.S. Pat. No. 7,090,296, the chair does not come with a design of assisting users to stand up, and cannot achieve the foregoing expected effect.

As described above, the conventional chairs only come with a design provided for lying, but lack of the function of assisting users to stand up. Obviously, the prior arts require improvements.

SUMMARY OF THE INVENTION

Therefore, it is a primary objective of the present invention to overcome the shortcomings of the prior art by providing a foldable assistive stand-up chair, wherein a chair mechanism is pivotally mounted onto a base support, and a driving component is provided for driving the chair mechanism to move with respect to the base support, such that when a user wants to stand up, the user's back and hip are supported forwardly and upwardly by a back frame and a chair frame respectively to achieve the assistive stand-up effect.

To achieve the foregoing objective, the invention provides an assistive stand-up chair comprising:

a base support, including a front base frame, a rear base frame, a fixing element disposed separately on both sides proximate to the top of the front and rear base frames for coupling the front and rear base frames, and the fixing element having a detachable design for detaching the front and rear base frames when the assistive stand-up chair is folded, and at least one connecting element disposed on both sides of the front and rear base frames, and both ends of the connecting element being coupled to the front and rear base frames respectively;

a chair mechanism, including a back frame, a chair frame, a leg frame and two armrests, and the chair frame being disposed between the front and rear base frames, and left and right sides proximate to the front of the chair frame being pivotally coupled to left and right sides proximate to the top of the front base frame, and left and right sides of the rear of the chair frame being pivotally coupled to left and right sides proximate to the bottom of the back frame, and left and right sides of a distal end at the front of the chair frame being pivotally coupled to left and right sides of the leg frame respectively, and left and right sides proximate to the top of the leg frame being pivotally coupled to a front end of the two armrests, and a rear end of the two armrests being pivotally coupled to left and right sides of the back frame; and

a driving component, including a driving device and a follower disposed at the bottom of the chair frame, and an end of the driving device being pivotally installed at the front base frame, and another end of the driving device being pivotally coupled to the follower, and an end or both ends of the driving device having a detachable design, and an end of the follower being pivotally coupled to the top of the rear base frame, and another end of the follower being pivotally coupled to the bottom of the back frame, and a pivoting position of the chair frame and the front base frame being used as an operating center, such that the driving device is driven to produce an assistive stand-up movement for the chair mechanism with respect to the base support.

To achieve the foregoing objective, the invention provides an assistive stand-up chair, comprising:

a base support, including a front base frame, a rear base frame, at least one connecting element disposed on left and right sides proximate to the top of the front and rear base frames for connecting the front and rear base frames, and a front stop portion and a rear stop portion extended from both ends of the connecting element respectively, such that when bottoms of the front and rear base frames are disposed apart from each other, the front and rear stop portions are stopped at front and rear sidewalls of the front and rear base frames for limiting positions of the front and rear base frames;

a chair mechanism, including a back frame, a chair frame, a leg frame and two armrests, and the chair frame being disposed between the front and rear base frames, and left and right sides proximate to the front of the chair frame being pivotally coupled to left and right sides proximate to the top of the front base frame, and left and right sides of the front of the chair frame being pivotally coupled to the leg frame respectively, and left and right sides of the rear of the back frame pivotally coupled to left and right sides proximate to the bottom of the back frame, and left and right sides proximate to the top of the leg frame being pivotally coupled to a front end of the two armrests, and a rear end of the two armrests having a dislocation design and pivotally coupled to left and right sides of the back frame; and

a driving component, including a driving device and a follower disposed at the bottom of the chair frame, and an end of the driving device being pivotally installed on the front base frame, and another end of the driving device being pivotally coupled to the follower, and an end of the follower being pivotally installed at the bottom of the back frame, and another end of the follower being pivotally coupled at the bottom of the rear base frame, and a pivoting position of the chair frame and the front base frame being used as an operating center and provided for the driving device to drive the chair mechanism, so as to provide an assistive stand-up movement with respect to the base support.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first preferred embodiment of the present invention;

FIG. 2 is a front view of a first preferred embodiment of the present invention;

FIG. 3 is a side view of a first preferred embodiment of the present invention;

FIG. 4 is a side view of a slightly supine status of a first preferred embodiment of the present invention;

FIG. 5 is a side view of a completely supine status of a first preferred embodiment of the present invention;

FIG. 6 is a side view of a first preferred embodiment of the present invention, showing an initial assistive stand-up status;

FIG. 7 is a side view of a first preferred embodiment of the present invention, showing an assistive stand-up status;

FIG. 8 is a side view of a first preferred embodiment of the present invention, showing a partial removal status at a first initial folding stage;

FIG. 9 is a side view of a first preferred embodiment of the present invention, showing a second folding stage;

FIG. 10 is a side view of a first preferred embodiment of the present invention, showing a third folding stage;

FIG. 11 is a side view of a first preferred embodiment of the present invention, showing a third folded status;

FIG. 12 is a schematic view of a first preferred embodiment of the present invention, showing a quick release structure at the position of a fixing element;

FIG. 13 is a perspective view of a second preferred embodiment of the present invention;

FIG. 14 is a front view of a second preferred embodiment of the present invention;

FIG. 15 is a side view of a second preferred embodiment of the present invention;

FIG. 16 is a side view of a slightly supine status of a second preferred embodiment of the present invention;

FIG. 17 is a side view of a completely supine status of a second preferred embodiment of the present invention;

FIG. 18 is a side view of a second preferred embodiment of the present invention, showing an initial assistive stand-up status;

FIG. 19 is a side view of a second preferred embodiment of the present invention, showing an assistive stand-up status;

FIG. 20 is a side view of a second preferred embodiment of the present invention, showing an adjustment to a pivoting position of an armrest and a back frame, and a first initial folding status;

FIG. 21 is a side view of a second preferred embodiment of the present invention, showing a second folding status;

FIG. 22 is a side view of a second preferred embodiment of the present invention, showing a third folding status;

FIG. 23 is a side view of a second preferred embodiment of the present invention, showing a folded status;

FIG. 24 is a schematic view of a conventional chair; and

FIG. 25 is a schematic view of another conventional chair.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The structural assembly, overall operation and technical characteristics of the present invention will become apparent with the detailed description of a preferred embodiment and the illustration of the related drawings as follows.

With reference to FIGS. 1 to 11 for the structure of a foldable assistive stand-up chair in accordance with a first preferred embodiment of the present invention, this embodiment is provided for illustrating the present invention, but not intended for limiting the structure of the invention.

In FIGS. 1 to 4, the foldable assistive stand-up chair in accordance with the first preferred embodiment of the present invention comprises:

a base support 1, having a front base frame 11 and a rear base frame 12 designed with a curved shape, which is substantially a U-shape, wherein the front and rear base frames 11, 12 of this embodiment are formed by bending metal pipes, and tops of the front and rear base frames 11, 12 are disposed adjacent to each other, and both sides proximate to the tops of the front and rear base frames 11, 12 being coupled to a fixing element 13 for coupling the front and rear base frames 11, 12, and the fixing element 13 having a detachable design for detaching the front and rear base frames 11, 12 to facilitate folding the stand-up chair, when the stand-up chair is folded, and a connecting element 14 being disposed at the front and rear base frames 11, 12 and proximate to the bottom of each fixing element 13, and both ends of the connecting element 14 being coupled to the front and rear base frames 11, 12 respectively, wherein both ends of the connecting element 14 of this embodiment are pivotally coupled, and the fixing element 13 and the connecting element 14 being provided for limiting positions of the front and rear base frames 11, 12, and bottoms of the front and rear base frames 11, 12 being disposed far apart from each other, such that the front and rear base frames 11, 12 are tilted and installed;

a chair mechanism 2, including a substantially n-shaped back frame 21 in this embodiment, an overall chair frame 22 substantially in a rectangular shape, a substantially U-shaped leg frame 23 and two armrests 24 disposed on left and right sides of the chair mechanism 2, wherein the back frame 21, the chair frame 22, the leg frame 23 and the two armrests 24 are made of pipes or rods, and the chair frame 22 are disposed between the front and rear base frames 11, 12, and left and right sides of the front proximate to the chair frame 22 are pivotally coupled to left and right sides proximate to the top of the front base frame 11, and left and right sides of a distal end at the rear of the chair frame 22 are pivotally coupled to left and right sides proximate to the bottom of the back frame 21, and left and right sides of a distal end of the front of the chair frame 22 are pivotally coupled to left and right sides of the leg frame 23 respectively, and left and right sides proximate to the top of the leg frame 23 are pivotally coupled to the front of the two armrests 24, and the rear of the two armrests 24 are pivotally coupled to left and right sides of the back frame 21, wherein the pivoting position of the armrests 24 and the back frame 21 is higher than the pivoting position of the chair frame 22 and the back frame 21; of course, the back frame 21 and the chair frame 22 of this embodiment respectively include a back cushion and a seat cushion (not shown in the figure) provided for users to sit;

a driving component 3, including a contractible driving device 31 and a follower 30 disposed at a rear side of the bottom of the chair frame 22, wherein an end of the driving device 31 is pivotally installed at the front base frame 11, and another end of the driving device 31 is pivotally coupled to the follower 30, and any of the two ends of the driving device 31 comes with a detachable design, and an end of the follower 30 is pivotally installed at the top of the rear base frame 12, and another end of the follower 30 is pivotally to the bottom of the back frame 21, and the driving device 31 of this embodiment is a hydraulic cylinder, a pneumatic cylinder, a lifting motor or a linear actuator that can be extended or contracted for operations, and the driving device 31 further comprises an operating interface (not shown in the figure) provided for making controls and adjustments by users, so as to facilitate controlling the movements of the assistive stand-up chair.

In this embodiment, the follower 30 comprises a link element 33, a driving rod 34 and two transmission elements 35, wherein an end of the link element 33 is pivotally coupled to the top of the driving device 31, and another end of the link element 33 is fixed to the middle position of the driving rod 34, and the axial direction of the driving rod 34 is perpendicular to the extending and contracting direction of the driving device 31, and both ends of the driving rod 34 are fixed to the two transmission elements 35 respectively, and an end (which is the rear end) of each transmission element 35 is pivotally coupled to left and right sides proximate to the bottom of the back frame 21, and another end (which is the front end) of each transmission element 35 proximate to the fixing element 13 is pivotally installed at left and right sides proximate to the top of the rear base frame 12. In addition, the aforementioned design uses the pivoting position of the chair frame 22 and the front base frame 11 as a moving center, such that the driving device 31 can be driven to produce an assistive stand-up movement of the chair mechanism 2 with respect to the base support 1.

With reference to FIGS. 3 to 5, FIG. 3 shows an application of the stand-up chair provided for a user to lie on the user's back. Assumed that a user (not shown in the figure) is sitting on the chair frame 22, and the user's back is leaning against the back frame 21, the driving and linking relations of components including the driving component 3 allow the stand-up chair to be set sequentially in the statuses as shown in FIGS. 4 and 5. Finally, the user can lie and rest on the chair as shown in FIG. 5. More specifically, the driving device 31 of the driving component 3 is retracted, such that components including the link element 33, the driving rod 34 and the transmission element 35 are linked to allow the back frame 21, the chair frame 22, the leg frame 23 and the armrests 24 of the chair mechanism 2 to produce movements like four link rods, so as to produce a tilted effect, wherein the back frame 21 and the leg frame 23 tend to be in a horizontal position after being tilted.

When the user wants to stand up, the chair may be situated at an initial status as shown in FIG. 3 or 5. Now, the driving and linking relations of components including the driving component 3 allow the stand-up chair to be set in the statuses sequentially as shown in FIGS. 6 and 7, such that the chair can assist and support users, particularly the elderly and mobility impaired people to stand up. During the movements, the driving device 31 of the driving component 3 is extended to produce a link effect for the components including the link element 33, the driving rod 34 and the transmission element 35, so as to allow the back frame 21, the chair frame 22, the leg frame 23 and the armrests 24 of the chair mechanism 2 to move like four link rods, and tend to be tilted to a vertical position, wherein the back frame 21 and the leg frame 23 tend to be in a vertical status, and the armrests 24 and the chair frame 22 are tilted more than the original status as shown in FIG. 3 to facilitate a user to hold the armrests 24 by both hands and produce an upward pushing force by the user's hip at the chair frame 22 when the user is standing up. Such design is helpful for assisting the user to stand up.

With reference to FIGS. 8 to 11 for stacking, folding and storing the stand-up chair of the aforementioned embodiment, the fixing element 13 as shown in FIG. 3 is separated from the front and rear base frames 11, 12 first, and the bottom of the driving device 31 is separated from the bottom of the front base frame 11. Of course, the fixing element 13 in this embodiment can be components such as bolts and nuts provided for a locking purpose. In addition, other components as shown in FIG. 12 can be used to achieve the installation and removal effects, and a design of a quick release structure 131 can be adopted at the position of the fixing element 13 to achieve the effect of connecting or separating the front and rear base frames 11, 12 quickly.

In summation, the stand-up chair of this embodiment is secured by components such as bolts and nuts, so that it is necessary to remove the bolts and nuts first before the user can stack and fold the base support 1, the chair mechanism 2 and the driving component 3, wherein the front and rear base frames 11, 12 and the driving device 31 can be folded towards the front of the stand-up chair, and the back frame 21 and the leg frame 23 can be pivotally folded towards the front and the rear of the stand-up chair, and the related stacking and folding processes and movements are indicated by arrows in FIGS. 8 to 10. The finally folded chair is shown in FIG. 11, and the foldable chair has the advantages of occupying not much storage space and providing an easy way for storage and transportation.

In summation of the description above, the first preferred embodiment of the present invention includes the chair mechanism mounted onto the base support, and the chair mechanism is driven and moved by the driving component, and the pivoting position of the chair frame of the chair mechanism and the front base frame of the base support is used as a pivoting center, such that the back frame, the chair frame, the leg frame and the armrests can be moved like four link rods with respect to the base support of the chair mechanism as shown in FIGS. 3 to 7. In addition to the lying function, the chair also assists users particularly the elderly and mobility impaired people to stand up. The assistive stand-up status of the chair is shown in FIG. 7. The present invention provides a more convenient and better mechanical chair to assist users to stand up.

With reference to FIGS. 13 to 15 for an assistive stand-up chair in accordance with a second preferred embodiment of the present invention, the assistive stand-up chair comprises the following elements:

A base support 4 includes a front base frame 41 and a rear base frame 42 designed in a curved shape, a connecting element 43 disposed separately on left and right sides proximate to the top of the front and rear base frames 41, 42 for coupling the front and rear base frames 41, 42, a front stop portion 431 and a rear stop portion 432 extended laterally and respectively from both ends of each connecting element 43, and when bottoms of the front and rear base frames 41, 42 are installed far apart from each other, the front and rear stop portions 431, 432 stop the front and rear sidewalls of the front and rear base frames 41, 42 respectively for limiting positions of the front and rear base frames 41, 42, and an axle shaft 44 is installed transversally between the middle section and the top of the front base frame 41.

A chair mechanism 5 includes a back frame 51, a chair frame 52, a leg frame 53 and two armrests 54 disposed on left and right sides of the chair mechanism 5 respectively, wherein the chair frame 52 is situated between the front and rear base frames 41, 42, and left and right sides proximate to the front of the chair frame 52 are pivotally installed on left and right sides proximate to the top of the front base frame 41, and left and right sides of a distal end of the front of the chair frame 52 are pivotally coupled to left and right sides of the leg frame 53, and left and right sides of the rear of the chair frame 52 are pivotally coupled to left and right sides proximate to the bottom of the back frame 51, and left and right sides proximate to the top of the leg frame 53 are pivotally coupled to the front end of the two armrests 54, and the rear end of the two armrests 54 come with a dislocation design, and pivotally coupled to left and right sides of the back frame 51, and the pivoting position of the armrests 54 and the back frame 51 is higher than the pivoting position of the chair frame 52 and the back frame 51. Of course, the back frame 51 and the chair frame 52 of the embodiment can include a back cushion and a seat cushion (not shown in the figure) provided for a user to sit.

A driving component 6 includes a contractible driving device 61 and a follower 60 disposed at the bottom of the chair frame 52, and an end of the driving device 61 is pivotally installed at the front base frame 41, and another end of the driving device 61 is pivotally coupled to the follower 60, and an end of the follower 60 is pivotally coupled to the bottom of the back frame 51, and another end of the follower 60 is pivotally installed at the top of the rear base frame 42, wherein the driving device 61 of this embodiment is a hydraulic cylinder, a pneumatic cylinder, a lifting motor or a linear actuator that can be extended or contracted during the operation, and the driving device 61 further includes an operating interface (not shown in the figure) provided for users to control and adjust the movement of the assistive stand-up chair.

In this embodiment, the follower 60 includes a link element 63, a driving rod 64 and two transmission elements 65, and an end of the link element 63 is pivotally coupled to another end of the driving device 61, and another end of the link element 63 is fixed onto a driving rod 64 disposed at the bottom of the chair frame 52, and an axial direction of the driving rod 64 is perpendicular to the extending and contracting direction of the driving device 61, and both ends of the driving rod 64 are coupled to the two transmission elements 65 respectively, and an end of each transmission element 65 is pivotally coupled to left and right sides proximate to the bottom of the back frame 51, and another end of each transmission element 65 is pivotally coupled to left and right sides proximate to the top of the rear base frame 42, wherein the pivoting position of the transmission element 65 and the rear base frame 42 is higher than the pivoting position of the connecting element 43 and the rear base frame 42. The pivoting position of the chair frame 52 and the front base frame 41 is used as a moving center, such that the chair mechanism 5 can be driven by the driving device 61 to produce an assistive stand-up movement with respect to the base support 4.

With reference to FIGS. 15 to 17, FIG. 15 shows an application of a user lying on the user's back. Assumed that a user (not shown in the figure) is sitting on the chair frame 52, and the user's back is leaning against the back frame 51, the driving and linking relation of components such as the driving component 6 allows the stand-up chair to be set in statuses as shown in FIGS. 16 and 17. Finally, the user can lie and rest on the chair in a supine position as shown in FIG. 17. More specifically, the driving device 61 of the driving component 6 is retracted to produce a linking effect for components including the link element 63, the driving rod 64 and the transmission element 65 to allow the back frame 51, the chair frame 52, the leg frame 53 and the armrests 54 of the chair mechanism 5 to be moved like four link rods, so as to produce a tilted effect, wherein the back frame 51 and the leg frame 53 tend to be disposed in a horizontal position after being tilted.

When the user wants to stand up, the chair may be situated at an initial status as shown in FIG. 15 or 17. Now, the driving and linking relation of components including the driving component 6 can be used for assisting users to stand up as shown in FIGS. 18 and 19, so that the chair can assist and support users such as the elderly and mobility impaired people to stand up. More specifically, the driving device 61 of the driving component 6 is extended to produce a linking effect for components including the link element 63, the driving rod 64 and the transmission element 65, so as to move the back frame 51, the chair frame 52, the leg frame 53 and the armrests 54 of the chair mechanism 5 like four link rods and tend to tilt them to a vertical position, wherein the back frame 51 and the leg frame 53 are almost in a vertical status, and the armrests 54 and the chair frame 22 are tilted more than the general original status as shown in FIG. 15. Therefore, a user can hold the armrests 54 by both hands and produce an upward force by pushing the chair frame 52 by the user's hip to stand up more easily, while the user is standing up. Obviously, such design can achieve the effect of assisting users to stand up.

With reference to FIGS. 20 to 23, this embodiment further comprises a pivoting portion 511 disposed at a position where the armrests 54 and the chair frame 52 are pivotally coupled to the back frame 51 and provided for folding and stacking the stand-up chair, and the pivoting portion 511 of this embodiment is a through hole, such that when the pivoting position of the armrests 54 and the back frame 51 is displaced and pivotally installed at the pivoting portion 511, the base support 4, the chair mechanism 5 and the driving component 6 can be stacked and folded. Of course, the same effect can be achieved by components such as bolts and nuts. When folded, the front and rear base frames 41, 42 can be pivotally turned and folded to the rear and front of the stand-up chair, and the back frame 51 and leg frame 53 can be pivotally turned and folded towards the front and rear of the stand-up chair. Of course, the pivoting position of the armrests 54 and the back frame 51 can come with a dislocation design. In other words, an integral slide slot (not shown in the figure) can be formed separately on both sides of the back frame 51 for pivotally coupling related components that are passed therein, so as to produce up and down displacements and facilitate the folding process. The folding process and related movements are indicated by arrows as shown in FIGS. 20 to 23. Finally, the folded chair as shown in FIG. 23 has the advantages of occupying not much space and providing an easy way for storage and transportation.

In summation of the description above, the second preferred embodiment of the present invention also includes a chair mechanism mounted onto the base support, and the chair mechanism is driven and moved by a driving component, wherein the pivoting position of the chair frame of the chair mechanism and the front base frame of the base support is used as a pivoting center, such that the back frame, the chair frame, the leg frame and the armrests of the chair mechanism can be moved with respect to the base support like four link rods as shown in FIGS. 15 to 19. The chair not just provides a function for a user to lie on the user's back only, but also supports and assists the user such as the elderly and mobility impaired people to stand up. The status of the chair for supporting and assisting users to stand up is shown in FIG. 19. Obviously, the design with an assistive stand-up function of the present invention is more convenient and useful than the traditional chairs. Different configurations of the present invention allow consumers to select a chair according to their requirements. As to manufacturers, the chairs can be manufactured selectively to minimize costs. In addition to the aforementioned advantages, different embodiments also show that the present invention can achieve the effect of assisting users to stand up conveniently.

While the invention has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those ordinarily skilled in the art without departing from the scope and spirit of the invention set forth in the claims. 

1. A foldable assistive stand-up chair, comprising: a base support, including a front base frame, a rear base frame, a fixing element separately disposed on both sides proximate to the top of the front and rear base frames for coupling the front and rear base frames, and the fixing element having a detachable design for detaching the front and rear base frames when the assistive stand-up chair is folded, and at least one connecting element being connected to the front and rear base frames respectively; a chair mechanism, including a back frame, a chair frame, a leg frame and two armrests, and the chair frame being disposed between the front and rear base frames, and left and right sides proximate to the front of the chair frame being pivotally coupled to left and right sides proximate to the top of the front base frame, and left and right sides of the rear of the chair frame being pivotally coupled to left and right sides proximate to the bottom of the back frame, and left and right sides of a distal end at the front of the chair frame being pivotally coupled to left and right sides of the leg frame respectively, and left and right sides proximate to the top of the leg frame being pivotally coupled to a front end of the two armrests, and a rear end of the two armrests being pivotally coupled to left and right sides of the back frame; and a driving component, including a driving device and a follower disposed at the bottom of the chair frame, and an end of the driving device being pivotally installed at the front base frame, and another end of the driving device being pivotally coupled to the follower, and an end or both ends of the driving device having a detachable design, and an end of the follower being pivotally coupled to a position proximate to the top of the rear base frame, and another end of the follower being pivotally coupled to a position proximate to the bottom of the back frame, and a pivoting position of the chair frame and the front base frame being used as an operating center, such that the driving device is driven to produce an assistive stand-up movement of the chair mechanism with respect to the base support.
 2. The foldable assistive stand-up chair of claim 1, wherein the back frame and the chair frame include a back cushion and a seat cushion respectively.
 3. The foldable assistive stand-up chair of claim 1, wherein the base support, the chair mechanism and the driving component are stacked and folded, if the front and rear base frames are separated, and the bottom of the driving device is separated from the bottom of the front base frame, wherein the front and rear base frames and the driving device are folded towards the front of the stand-up chair, and the back frame and the leg frame are pivotally turned and folded towards the front and the rear of the stand-up chair respectively.
 4. The foldable assistive stand-up chair of claim 1, wherein the driving device is a hydraulic cylinder, a pneumatic cylinder, a lifting motor or a linear actuator that can be extended and contracted.
 5. The foldable assistive stand-up chair of claim 1, wherein the follower includes a link element, a driving rod and two transmission elements, and an end of the link element is pivotally coupled to the top of the driving device, and another end of the link element is fixed to the center of the driving rod, and the driving rod is axially perpendicular to an extending and contracting direction of the driving device, and both ends of the driving rod are fixed to the two transmission elements respectively, and an end of each transmission element is pivotally coupled to left and right sides proximate to the bottom of the back frame, and another end of each transmission element proximate to the fixing element is pivotally coupled to left and right sides proximate to the top of the rear base frame.
 6. The foldable assistive stand-up chair of claim 1, wherein the fixing element includes a quick release structure for quickly connecting or detaching the front and rear base frames.
 7. A foldable assistive stand-up chair, comprising: a base support, including a front base frame, a rear base frame, at least one connecting element separately disposed on left and right sides proximate to the top of the front and rear base frames for connecting the front and rear base frames, and a front stop portion and a rear stop portion extended from both ends of the connecting element respectively, such that when the bottoms of the front and rear base frames are disposed apart from each other, the front and rear stop portions are stopped at front and rear sidewalls of the front and rear base frames for limiting positions of the front and rear base frames; a chair mechanism, including a back frame, a chair frame, a leg frame and two armrests, and the chair frame being disposed between the front and rear base frames, and left and right sides proximate to the front of the chair frame being pivotally coupled to left and right sides proximate to the top of the front base frame, and left and right sides of the front of the chair frame being pivotally coupled to the leg frame left and right sides respectively, and left and right sides of the rear of the back frame pivotally coupled to left and right sides proximate to the bottom of the back frame, and left and right sides proximate to the top of the leg frame being pivotally coupled to a front end of the two armrests, and a rear end of the two armrests having a dislocation design and pivotally coupled to left and right sides of the back frame; and a driving component, including a driving device and a follower disposed at the bottom of the chair frame, and an end of the driving device being pivotally installed on the front base frame, and another end of the driving device being pivotally coupled to the follower, and an end of the follower being pivotally installed at the bottom of the back frame, and another end of the follower being pivotally coupled to the bottom of the rear base frame, and a pivoting position of the chair frame and the front base frame being used as an operating center and provided for the driving device to drive the chair mechanism to provide an assistive stand-up movement with respect to the base support.
 8. The foldable assistive stand-up chair of claim 7, wherein the back frame and the chair frame include a back cushion and a seat cushion respectively.
 9. The foldable assistive stand-up chair of claim 7, further comprising a pivoting portion disposed at the back frame pivotally coupled to between the armrests and the chair frame and provided for folding the stand-up chair, and the base support, the chair mechanism and the driving component can be stacked and folded, if the pivoting portion is pivotally installed at a pivoting position of the armrests and the back frame, wherein the front and rear base frames are pivotally turned towards the rear and front of the stand-up chair respectively, and the back frame and the leg frame are turned towards the front and rear of the stand-up chair respectively for folding the stand-up chair.
 10. The foldable assistive stand-up chair of claim 7, wherein the driving device is a hydraulic cylinder, a pneumatic cylinder, a lifting motor or a linear actuator that can be extended and contracted.
 11. The foldable assistive stand-up chair of claim 7, wherein the follower includes a link element, a driving rod and two transmission elements, and an end of the link element is pivotally coupled to another end of the driving device, and another end of the link element is fixed onto a driving rod situated at the bottom of the chair frame, and the driving rod is axially perpendicular to an extending and contracting direction of the driving device, and both ends of the driving rod are coupled to the two transmission elements respectively, and an end of each transmission element is pivotally coupled to left and right sides proximate to the bottom of the back frame, and another end of each transmission element is pivotally coupled to left and right sides proximate to the top of the rear base frame, wherein the pivoting position of the transmission element and the rear base frame is higher than the pivoting position of the connecting element and the rear base frame. 